Normally, when mechanically recognizing a music score, staff recognition and recognition of paragraphs as shown in FIG. 29 are carried out, thereafter, the staff is eliminated. Then, using various methods, a head of a note, such as a black head b shown at (a) in FIG. 30 or a white head w shown at (b) in the same figure, a stem t, continuous with the head, shown at (c) in the same figure, a flag f, continuous with the stem, shown at (d) in the same figure, and others are recognized.
In contrast, notation of a drum score, which is a music score of a drum set, is not fixed based on the historical cause of the musical instrument and the cause on playing.
Since there exists no general notation, if recognition of a particular notation is aimed at, generality of drum score recognition is lost.
On the other hand, if various notations are aimed to be recognized, it is not possible, only by recognizing a notated sign according to the notation itself, to specify which drum instrument (drum tone) plays that note, and thus the drum score can not be played as it is.
Further, if aiming to recognize the drum score regardless of a particular notation as described above, it is required, for correctly playing the recognition results, to designate what drum tone (drum instrument) is actually represented by that sign (including a note). A user may carry out such designation, but in this case, it is necessary that the user knows well the drum score notation. Further, for such designation, a complicated interface is used and a designation operation becomes complicated so that numerous correction steps are required, resulting in increase of the total correction cost.
In addition, even if a notation type is designated before recognizing a drum score and recognition is executed based on the designated notation type so as to make unnecessary correction after the recognition, the user side is similarly required to have the precise knowledge about the notation.
The foregoing problems have impeded dealing with the drum score in the conventional music score recognition technique.
Among heads notated on a drum score, those notes other than a black head or a white head like in a normal music score are described by thin lines, such as (X) and (.diamond.), and there exist various other types. Therefore, they can not be detected using the thick/thin separation (see JP-A-9-97060: method wherein a portion formed by a thin line is separated from image data, then a sign formed by the thin line is detected therefrom, then a thick sign is detected from the remaining image so as to recognize a sign appearing on a music score) or the ellipse detection (method wherein a black head or a white head used as a head of a normal note is recognized using the equation of ellipse) which have been used for note recognition of the normal music score.
Other than the foregoing, there exist problems, which can not be solved by the conventional method, such as tie coupling to heads and a chord having two or more heads abutting in the longitudinal direction. There are further problems, which do not exist in the normal music score, such that the position where a head is coupled to a stem differs depending on a music score and that there is a note of a type wherein a head is located on the midway of a stem so as to cut the stem.
The present invention has been made in view of the foregoing problems of the prior art. The first object of a structure of the present application is to provide a structure which can recognize notations of drum scores described by various notations for conversion into a playable data format with less operations.
The second object of a structure of the present application is to provide a structure which enables recognition of a drum note in a drum score different from a normal music score for conversion into a playable and/or displayable data format.